<template>
    <label class="l-radio" :class="{'is-checked': label === model}">
        <span class="l-radio__input">
            <span class="l-radio__inner"></span>
            <input
            type="radio"
            class="l-radio__original"
            :value="label"
            :name="name"
            v-model="model"
            >
        </span>
        <span class="l-radio__label">
            <slot></slot>
            <!-- 如果插槽中没有传递内容，则把label当成内容 -->
            <template v-if="!$slots.default">{{label}}</template>
        </span>
    </label>
</template>

<script>
export default {
  name: 'LRadio',
  inject: {
    RadioGroup: {
      default: ''
    }
  },
  // 需要提供一个计算属性 model
  computed: {
    // 创建model属性，是因为不能违反父子组件中单向数据流的特点
    model: {
      get () {
        return this.isGroup ? this.RadioGroup.value : this.value
      },
      set (value) {
        // 触发父组件给当前组件注册的input事件
        this.isGroup ? this.RadioGroup.$emit('input', value) : this.$emit('input', value)
      }
    },
    isGroup () {
      // 用于判断radio是否被radioGroup所包裹
      return !!this.RadioGroup
    }
  },
  props: {
    label: {
      type: [String, Number, Boolean],
      default: ''
    },
    value: null,
    name: {
      type: String,
      default: ''
    }
  }
}
</script>

<style lang="scss">
.l-radio {
    color: #606266;
    font-weight: 500;
    line-height: 1;
    position: relative;
    cursor: pointer;
    display: inline-block;
    white-space: nowrap;
    outline: none;
    font-size: 14px;
    margin-right: 30px;
    -moz-user-select: none;
    -webkit-user-select: none;
    -ms-user-select: none;

    .l-radio__input {
      white-space: nowrap;
      cursor: pointer;
      outline: none;
      display: inline-block;
      line-height: 1;
      position: relative;
      vertical-align: middle;

      .l-radio__inner {
        border: 1px solid #dcdfe6;
        border-radius: 100%;
        width: 14px;
        height: 14px;
        background-color: #fff;
        position: relative;
        cursor: pointer;
        display: inline-block;
        box-sizing: border-box;

        &::after {
          width: 4px;
          height: 4px;
          border-radius: 100%;
          background-color: #fff;
          content: '';
          position: absolute;
          left: 50%;
          top: 50%;
          transform: translate(-50%, -50%) scale(0);
          transition: transform 0.15s ease-in;
        }
      }

      .l-radio__original {
        opacity: 0;
        outline: none;
        position: absolute;
        z-index: -1;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        margin: 0;
      }
    }

    .l-radio__label {
      font-size: 14px;
      padding-left: 10px;
    }
  }
  // 选中时样式
  .l-radio.is-checked {
    .l-radio__input {
      .l-radio__inner {
        border-color: #409eff;
        background: #409eff;
        &::after {
          transform: translate(-50%, -50%) scale(1);
        }
      }
    }
    .l-radio__label {
      color: #409eff;
    }
  }
</style>
